Sasori Vader

Sasori Vader was a changeling entity who lived in a Jawa sandcrawler on the planet Tatooine at the time of the Galactic Civil War. Its true form was that of a giant scorpion with red glowing eyes, but it could turn into the shape of the Sith Lord Darth Vader.

In 0 BBY, Sasori Vader, having somehow managed to take over a Jawa sandcrawler, imprisoned two Jawas (who had also managed to kidnap R2-D2 earlier) and incarcerate them in the bridge area of what used to be their sandcrawler. The young Luke Skywalker then made his way to the sandcrawler in order to free his droid friend and confront Sasori Vader, who had taken the shape of Darth Vader. During the ensuing fight, Sasori Vader turned back into its true form, but he was eventually defeated and killed by Skywalker.

Text and facts from the “Sasori Vader” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.